To install the AIV files; first make a backup of your old files and replace the old files with the new files, which you find in the FAPLZ_AIV_files_Improfed.zip .
To install the AIC (the AIC file is the .json file you find in the .zib you downloaded here), you have to download the latest Unoffical Crusader Patch first (read IMPORTANT text) and put the AIC file in the sub folder resources\aic (the sub folder are located in the UCP folder).
Then run the UnofficialCrusaderPatchGUI.exe , select your language, the Stronghold folder and after that you can find a tab called: aic.
There you have to choose the AIC file with the same name like you put in the sub folder.
If you done it correctly, you can play now with the changed AI.
With the UCP you can change more then only the AIC and AIV for example, try it out...